A Simulation of the Optical Attenuation of TPB Coated Light-guide Detectors

TL;DR

This paper uses simple simulations to explore light attenuation in acrylic light-guides with TPB coating, revealing non-exponential effects and environmental differences between air and argon, with predictions validated against experimental data.

Contribution

It introduces a toy model simulation approach to understand complex light attenuation behaviors and compares predictions with actual measurements in different environments.

Findings

Non-exponential attenuation effects observed

Model predicts attenuation in argon from air data

Improved fit over simple exponential models

Abstract

This note describes simple simulations which were performed in order to understand the attenuation behaviors of acrylic light-guides operated in air and argon, which were characterized in \cite{Baptista:2012bf}. Whilst these simulations are only at the level of sophistication of a toy model, they illustrate interesting non-exponential light attenuation effects and the differences between operating light-guide based detectors in argon and air environments. We investigate the effects of surface absorption, surface roughness and wavelength dependence, and use a model tuned on the light-guide attenuation curve measured in air to make a prediction of the light-guide attenuation curve in argon. This curve is compared with data from a liquid argon test stand, and an improvement over a simple exponential model is observed.